JavaScript: Remove Duplicates from an Array

1. Introduction

Duplicate entries in arrays can sometimes lead to skewed data processing or redundancy issues. Removing duplicates from an array is therefore a crucial task in many scenarios. Thankfully, JavaScript offers multiple methods to achieve this. In this guide, we'll discuss how to remove duplicates from an array using the Set object.

2. Program Overview

Our journey through this guide will involve:

1. Initializing an array with some duplicate values.

2. Removing the duplicates using the Set object.

3. Displaying the array without duplicates.

3. Code Program

let numbers = [1, 2, 2, 3, 4, 4, 5];  // Array with duplicate values
let uniqueNumbers;  // Variable to store the unique values from the array

// Using the Set object to remove duplicates
uniqueNumbers = [ Set(numbers)];

console.log("Original Array:", numbers);
console.log("Array without Duplicates:", uniqueNumbers);


Original Array: [1, 2, 2, 3, 4, 4, 5]
Array without Duplicates: [1, 2, 3, 4, 5]

4. Step By Step Explanation

1. Array Initialization: We commence by defining an array numbers that contains some duplicate values.

2. Removing Duplicates using Set: JavaScript's Set is a built-in object that stores unique values. When an array is converted into a set, any duplicate entries are automatically removed. To convert this set back into an array, we use the spread operator (...).

3. Storing and Displaying the Result: The array devoid of duplicates is stored in the uniqueNumbers variable. Using console.log, we then showcase both the initial array and the modified array without the duplicates.